Rice Lake 480 Legend Series Digital Weight Indicator Installation Manual - Manual (Page 62)

58 480 Installation Manual
9.8 Conversion Factors for Secondary Units
The 480 has the capability to mathematically convert a weight into many different types of units and instantly
display those results with a press of the
UNIT key.
Secondary units can be specified on the FORMAT menu using the SECNDR parameter.
Multipliers are preconfigured within the indicator.
Ensure that the secondary decimal point position is set appropriately for the scale capacity in the secondary
units. If the converted value requires more digits than are available, the indicator will display an overflow
message (OVERFL).
For example, if the primary units are short tons, secondary units are pounds, and the secondary decimal point is set to
8888.88, the indicator will overflow if 5 tons or more are applied to the scale. With 5 tons applied, and a conversion factor
of 2000, the secondary units display needs five digits to the left of the decimal point to display the 10000 lb secondary
units value.
9.9 Digital Filtering
Digital filtering can be used to create a stable scale reading in challenging environments. The 480 has three
filtering methods that can be set; Sample rate, Digital filter, and Stability filter.
9.9.1 Sample Rate:
The Sample rate should be set first. Better stability is achieved with a lower sample rate setting, so 5 Hz is more
stable than 40 Hz. With the other filters disabled, determine the amount of instability that is present. Convert this
instability to display division. The number of display division of instability will be used to set the threshold of the
digital filter.
9.9.2 Digital Filter:
The digital filter is an advanced adaptive filter that has two parameters to set the filter settling and response times:
sensitivity and threshold. The digital filter can be set on or off with the parameter
DIGFIL .
Digital Filtering Sensitivity
Digital filtering sensitivity ( DFSENS ) controls the stability and settling time of the scale. The sensitivity parameter
can be set to heavy, medium, or light. A heavy setting will result in an output that is more stable and will settle
more quickly than that of a light. However, small changes in weight data (a few grads) on the scale base will not be
seen as quickly.
If the difference in typical subsequent weight values on your scale will be only a few grads, use a light setting. If
using a truck scale where the changes in subsequent weight values will be 100s of grads, a heavy setting will be
more appropriate.
Digital Filtering Threshold
Digital filtering threshold ( DFTHRH ) should be set for the amount of observed noise in the system. This parameter
can be set in the range of 0 to 999999 display divisions. When a new sampled weight value is acquired, the
adaptive filter compares the new value to the previous (filtered) output value. If the difference between the new
value and the previous output value is greater than the
DFTHRH parameter (displayed division) the adaptive filter
output is flushed. The newly acquired sample value replaces the filtered output. If the difference between the new
value and the previous output value is less than the
DFTHRH parameter, the two values are averaged together using
a weighted average. This is based on the amount of the difference, time the system has been stable, and selected
DFSENS value.
9.9.3 Stability Filter:
The Stability filter is between the Adaptive Digital Filter and the Displayed Weight. When the weight change is
within the motion band parameter, a rolling average filter is applied to the displayed value. The parameters used in
this filter are Motion band, Read Stability and Read Motion.
Motion Band
Set the Motion Band ( MOTBAN ) for the amount of weight fluctuation (displayed divisions) that is acceptable as a
stable condition. For bench and floor scales is this usually 1 display division. For truck scales, this is usually 3
display divisions.
Note